Product Description:

The RAC 2.3-250-460-A0I-Z1 is an AC main spindle drive controller manufactured by Bosch Rexroth Indramat and supplied in the RAC Spindle Drive Controllers series. Designed for machine tool automation, the unit converts three-phase mains power into a regulated output that supports constant spindle speed and stable torque during cutting, drilling, and grinding operations. In spindle service, this kind of control helps the motor hold commanded speed as the cutting load changes, which is important for repeatable surface finish, predictable tool behavior, and steady material removal across a wide operating range. That behavior also supports machining processes where sudden speed loss could affect dimensional accuracy during long or demanding passes.

Its continuous output capability reaches 250 A, allowing the controller to supply large spindle motors during heavy material removal and sustained machining passes. The power section accepts 3 x AC 400 V, 50 Hz, ±15% or 3 x AC 460 V, which supports installation on common industrial mains systems without a separate voltage adaptation stage. Speed reference signals are provided through an analog (+/- 10 V) input, and thermal management is handled by a built-in blower so the unit can dissipate heat within a cabinet layout. The analog reference allows a CNC or PLC to send a proportional speed command through a familiar control format. Parameter access and field wiring are arranged on connector X4, 9 poles, which keeps the control and connection points in a single location and supports orderly cable routing.

Dynamic braking energy is absorbed by an additional bleeder, which helps protect the DC link during rapid spindle deceleration and repeated speed changes. Position forwarding is provided through an incremental encoder output, and the drive is supplied without an additional encoder input for extra feedback channels. The unit is Series 2 and Version 3, indicating the product generation used for this drive type. Because the drive does not include that extra encoder input, any added feedback device would need to be handled outside this interface set.